High Speed type positioning mechanism

ABSTRACT

A high speed type element positioning mechanism has a type head member having therein a plurality of type elements and a type head shaft on which the type head is mounted. The type head member has a spherical surface thereon through which the axis of the type head shaft extends, the type elements being mounted in the type head member with the faces thereof on the spherical surface and movable in the type head member for being projected beyond the spherical surface. The type elements lie along latitudinal circles on the surface the centers of which lie on the axis of the type head shaft, the type elements in adjacent latitudinal circles being substantially aligned along longitudinal circles extending from the point of intersection of the type head shaft axis and the spherical surface. The type head shaft is pivotally mounted for pivotal movement around a point corresponding to the center of the sphere of which the spherical surface forms a part, and a type hammer is positioned adjacent the type head for striking a type element for projecting it beyond the spherical surface for carrying out a printing action. A first drive means is coupled to the type head shaft for rotating the shaft in response to a signal corresponding to a character to be printed for rotating the type head member for aligning the type member corresponding to the character to be printed in a plane with the type hammer and the type head shaft, and a second drive means is coupled to the type head shaft for pivoting the type head shaft in the plane for aligning a type element in one of the circles with the type hammer.

United States Patent [191 Fujio et al.

[ 1 Nov. 25, 1975 HIGH SPEED TYPE POSITIONING MECHANISM [73] Assignee: Yamura Kabushikikaisha Shinko Seisakusho, Hanamaki, Japan 22 Filed: Nov. 29, 1974 [21] Appl. No.: 528,470

[30 Foreign Application Priority Data Dec. 3, 1973 Japan 48-136339 [52] U.S. Cl. 197/53; 197/52 [51] Int. CL? 841.] 1/32 [58] Field of Search 197/48, 52, 53, 54, 55; 178/34 [56] References Cited UNITED STATES PATENTS 2,838,156 6/1958 Griffith 197/53 3,295,652 l/l967 Sasaki 197/53 3,397,766 8/1968 Spalinger.. 197/53 X 3,493,090 2/1970 Liles 197/52 X FOREIGN PATENTS OR APPLICATIONS 1,122,225 7/1968 United Kingdom 197/53 Primary Examiner1-Iarland S. Skogquist Attorney, Agent, or Firm-Wenderoth, Lind & Ponack ABSTRACT A high speed type element positioning mechanism has a type head member having therein a plurality of type elements and a type head shaft on which the type head is mounted. The type head member has a spherical surface thereon through which the axis of the type 'head shaft extends, the type elements being mounted in the type head member with'tl'ie faces thereof on the spherical surface and movable in the type head member for being projected beyond the spherical surface. The type elements lie along latitudinal circles on the surface the centers of which lie on the axis of the type head shaft, the type elements in adjacent latitudinal circles being substantially aligned along longitudinal circles extending from the point of intersection of the type head shaft axis and the spherical surface/The type head shaft is pivotally mounted for pivotal movement around a point corresponding to the center of the sphere of which the spherical surface forms a part,

and a type hammer is positioned adjacent the type head for striking a type element for projecting it beyond the spherical surface for carrying out a printing action. A first drive means is coupled to the type head shaft for rotating the shaft in response to a signal corresponding to a character to be printed for rotating the type head member for aligning the type member corresponding to the character to be printed in a plane with the type hammer and the type head shaft, and a second drive means is coupled to the type head shaft for pivoting the type head shaft in the plane for aligning a type element in one of the circles with the type hammer.

1 Claim, 3 Drawing Figures US. Patent Nov. 25', 1975 3,921,787

( PRIOR ART) HIGH SPEED TYPE POSITIONING MECHANISM The present invention relates to high speed type ele'-. ment positioning mechanism for a teleprinter or a typewriter.

Ina conventional type element positioning mecha-- nism, the pallet head, a typical example of which is shown in FIG. l, hasthe type elements I housed in the pallet P in rows the X and Y-directions, respectively, and when a certain type element is to be actuated to print the character thereon, the pallet P is'moved a certain distance in the X and Y directions, respectively, to

position the type element to be actuated in front of a type hammer 2, and the type hammer 2 isthen driven against the tail of the type element 1 instantaneously to type element to print a desired character. After the character is printed, the typeelement is returned to the position shown in FIG. I by a return spring which is spherical surface which, have the centers thereof on the compressed when the type elementisprojected;

However, when this conventional arrangement is used,'it is necessary to move the pallet P linearly both in the X and Y directions for positioning the desired type element, making the positioning mechanism complicated and making it difficult-to position a desired type element at high speed.

It is an object of the present invention to providea pallet head and an associated positioning mechanism to overcome these defects, and to obtain a type positioning mechanism which has a simple structure and which is capable of positioning a type element at high speed by means of a pallet head housing a large number of type elements.

The mechanism of the present invention has a pallet head, which was formerly box-shaped, which has a head member with a surface forming part of a sphere,

and the type elements are positioned along the circumference of latitudinal circles and longitudinal circles on the spherical surface of this head member. That is rows of type elements are provided along the circumferences of circles at a plurality of radial positions. A desired type element in the type head thus constructed is first moved toward the desired printing position .by' rotating the type head on the axis connecting the centers of the latitudinal circles formed by the rows of type elements and the geometrical center of the sphere. 'As a result,

each type element is moved along the circumference of V the latitudinal circle formed by a row of type elements to which the desired type element belongs. In addition, the whole type head is moved in an arc in a plane'con- .taining the centers of said circles and the center of the sphere with the center of the sphere as the pivot point.

The two movements can coincide with each other. It is possible to use a servo motor or a stepping motor as a drive means for carrying out the two movements.

The following is a description of one embodiment of the invention, reference being made to the accompanying drawings, in which:

FIG. I is a schematic perspective view of a conventional pallet head for type elements;

FIG. 2 is a plan view of an embodiment of the positioning mechanism of the present invention; and

FIG. 3 is a side elevation, partly in section, of the mechanism of FIG. 2.

FIGS. 2 and 3 show the type positioning mechanism with rows of type elements 12 arranged in two circles o'nthe spherical surface of a head member 5, as 'de-' scribed above, and FIG. 3 is a partial sectional view of 5 the principal part of the head member. The mechanism support 7 integrally formed as an extension on an or- -,direction', for instance a servo motor ora stepping mo-. tor, is provided, and the shaftthereof is connected to typefelements lie on latitudinal circles 0 c on the axis of rotation 6a of the type head shaft 6. The individual typeelements in the respective latitudinal circles are also aligned along longitudinal circles extending along the spherical surface 5a from the point 6b at which the axis of the type head shaft 6 intersects the I surface 5a. A return spring 13 is positioned around and hammer when it has been moved to the printing positype element to the initial position. Carriage guides 15 and 16 are provided on the underframes along which the carriage 4 is movable. A cam follower '17 is pivot ally mounted on the shaft support 7and.engages" an .ec.

centric cam (not visible in thedrawing) on the shaftof the motor 11. Theaxis of the type head shaft 6 and the surface 5a forms a part. The orthogonal driving and 'a gear mechanism whichtransmits the rotation of the drive shaft to the type head shaft 6 at a suitable speed ratio.

direction along the latitudinal and longitudinal circles of type elements takes place. The motor 10 receives an electric signal corresponding to a character to be printed and is rotated through a suitable angle under the control of a conventional motor control circuit, the illustration of which is omitted. The motor 10 transmits this rotation to the drive shaft 9 coupled directly thereto. The rotation of the drive shaft 9 is transmitted to the type head shaft 6 through the orthogonal driving and transmitting mechanism 8, which is coupled to the drive shaft 9 by suitable means such as a spline. Accordingly, the type head member 5 fixed to the tip of the type head shaft 6 is rotated through a suitable angle to position the type element 12 in one of the latidudinal circles 0,, 0 etc. of type elements 12 containing the character corresponding to the electrical signal received by motor 10 into a position in the plane P conthogonal driving and connecting mechanism 8. A drive shaft 9is rotatably mounted on the underframe of a printer oratype writer. selective driving motorlO for providing driving movement in the circumferential I the, drive ,shaft,' 9. A- selectingidriving motor 11, for inwstanCe'afSerVO'niotoror a steppingmotor, or'a tortiu e motor or other electromagnetic motive device, is.- mounted on the carriage 4. The'typeflelements 12 are arranged in the head member 5 with the faces thereof on thespherical surface '5a of a sphere and the rows of in engagement with each type element 12 and in engagement with the head element 5 and which is ordi-. narily in the expanded or relaxed state, as shown in. FIG. 3, When'the type element is struck by the type" tion, the spring is compressed, and acts to return the connecting mechanism 8 is composed of, for'instance,

In operation, when a certain character is to be, printed, selective driving of the head member 5 in the v taining the type hammer l4 and the axis 6a of the type head shaft 6. The motor 11 receives an electric signal corresponding to the character to be printed in the same way as described above and is rotated through a suitable angle by a commonly known means through a motor control circuit the illustration of which is omitted. The rotation of the motor 11 is transmitted to the cam follower 17 through the eccentric cam and further to the rotary shaft support 7. As a result, the rotary shaft support 7 is moved upward or downward in plane P in FIG. 3 around point 9a as the pivot, if necessary, to bring the circle 0,, c etc. with the type element corresponding to the signal received immediately in front of the type hammer 14. The type hammer is driven by a commonly known drive circuit, the illustration of which is omitted, at a suitable time to strike the tail of the type element 12 thus positioned in alignment therewith. The type element 12 which is struck is projected out of the type head member and the face thereof comes in contact with the ink ribbon or the like interposed between the face of the type element and a recording medium such as paper or the like to press the ribbon against the recording medium to'print the desired character on it. After the character is printed, the type hammer is returned to the initial position by a suitable means and the type element 12 is also returned to the position shown in FIG. 3 by the restoring force of the return spring 13.

When a gear mechanism is used in the orthogonal driving and connecting mechanism 8, the movement of the type head member 5 in plane P in FIG. 3 is attended by a slight rotation of the type head member on the type head shaft 6, but this problem can be solved by spacing type elements 12 on the circumference of the circles c c etc. slightly out of line in the direction of the longitudinal circles. That is, in the rows of type elements arranged on the circumferences of, for instance, two adjacent latitudinal circles, a type element on the circumference of the one circle and one on the circumferences of the other circle are not necessarily on the same longitudinal circle, but are arranged slightly out of line.

A disc or the like for detecting an angular position, illustration of which is omitted, can be provided on the type head shaft 6 or the drive shaft 9 for confirmation or detection of type positioning action,

After one character is printed, the carriage 4 is moved along the carriage guides 15 and 16 by a commonly known means and stands ready for the next printing action at a new printing position on the record ing medium.

As described in detail above, according to the present invention, there is provided a type head member on which type elements are arranged in a plurality of latitudinal circles and a plurality of longitudinal circles and so that the faces thereof lie on a spherical surface, and this type head member is rotatably supported on type head shaft and the type head shaft is oscillatably mounted on a drive shaft as the pivot, thereby making it possible to position a type element by rotation and/or oscillation simultaneously with each other and, also making it possible to use a servomotor or a stepping motor as a drive source for these two movements. As a result, the advantage of the above described invention is that the type positioning mechanism has a simple construction and is stable at high speed.

What is claimed is: i

. l. A high speed type element positioning mechanism,

' comprising a type head member having therein a plurality of type elements, a type head shaft on which said type head is mounted, the type head member having a spherical surface thereonthrough which the axis of said i type head shaft extends, said type elements being mounted in said type head member with the faces thereof on said spherical surface and movable in said type head member for being projected beyond said spherical surface, said type elements lying along latitudinal circles on said surface the centers of which lie on the axis of said type head shaft, the type elements in adjacent latitudinal circles being substantially aligned along longitudinal circles extending from the pointof intersection of said type head shaft axis and said spherical surface, said type head shaft being pivotally mounted for pivotal movement around a point corresponding to the center of the sphere of which said the type member corresponding to the character to be' printed in the plane with said type hammer, and a second drive means coupled to said type head shaft for pivoting said type head shaft in said plane for aligning a type element in one of said circles with said type hammer. 

1. A high speed type element positioning mechanism, comprising a type head member having therein a plurality of type elements, a type head shaft on which said type head is mounted, the type head member having a spherical surface thereon through which the axis of said type head shaft extends, said type elements being mounted in said type head member with the faces thereof on said spherical surface and movable in said type head member for being projected beyond said spherical surface, said type elements lying along latitudinal circles on said surface the centers of which lie on the axis of said type head shaft, the type elements in adjacent latitudinal circles being substantially aligned along longitudinal circles extending from the point of intersection of said type head shaft axis and said spherical surface, said type head shaft being pivotally mounted for pivotal movement around a point corresponding to the center of the sphere of which said spherical surface forms a part, a type hammer positioned adjacent said type head for striking a type element for projecting it beyond said sperical surface for carrying out a printing action and lying in a plane with the axis of said type head shaft, a first drive means coupled to said type head shaft for rotating said shaft in response to a signal corresponding to a character to be printed for rotating said type head member for aligning the type member corresponding to the character to be printed in the plane with said type hammer, and a second drive means coupled to said type head shaft for pivoting said type head shaft in said plane for aligning a type element in one of said circles with said type hammer. 